The present invention relates to a display driver and a touch control circuit of a display panel having a touch sensor mounted thereon, and particularly relates to a display driver and a touch control circuit which are capable of being suitably used for a reduction in power consumption of a circuit.
Hitherto, on-cell types in which a display panel and a touch panel are independent of each other have been the mainstream. However, in recent years, in-cell types capable of achieving a further reduction in thickness in which a display panel and a touch panel are integrated with each other have been widespread, particularly, in mobile panel modules. Since the display panel and the touch sensor are independent of each other in on-cell types, independent-type separate chips are also mainly used for the display driver and the touch controller. In the separate chips, display driving and sensing are generally performed in an asynchronous manner. On the other hand, since the display panel and the touch sensor share circuits in the in-cell types, display driving and sensing cannot be performed simultaneously, and thus types in which display driving and sensing are performed alternately in a time-division manner have been proposed.
JP-A-2012-59265 discloses a display device in which a touch sensor and a display element of an in-cell type are operated alternately in a time-division manner and a method of driving the same. The sensing of the touch sensor and the driving of the display element are performed alternately in a time-division manner. This is a system in which one frame is divided into a display mode and a touch sensing mode, and a gate driver, a data driver and a touch controller are controlled by a timing controller so that both the modes are executed alternately. In this system, the high accuracy of touch detection is realized by intermittently performing image display for each of several lines, and performing touch sensing in a period in which image output from a display driver is stopped. Since noise of a signal for driving the display element is not mixed into a detection signal of the touch sensor, the influence of noise can be alleviated.